INDIO — Snoop Dogg and Dr. Dre may not have raised the dead in their headlining set late Sunday night at the Coachella Valley Music & Arts Festival, at least not literally. But, in addition to cameos by the alive-and-well Eminem, Wiz Khalifa, Kendrick Lamar and 50 Cent, they did have a high-tech guest appearance (in a manner) by a hip-hop icon who died 16 years ago.

Rapper Tupac Shakur, who was shot to death in 1996 at the age of 25, was featured Sunday — in hologram form — doing a posthumous duet with Snoop on "2 of Amerikaz Most Wanted." Earlier in the set, Dre and Snoop also paid tribute to another deceased rapper, Nate Dogg, who died last year following a series of strokes. "Shakur's "Hail Mary" was also included Sunday night.

The two homages to fallen colleagues came as part of a 24-song set that drew the largest audience of the sold-out, three-day Coachella festival, which returns Friday for a second weekend featuring the same 140-act lineup that performed this weekend. Twenty percent of the audience, an estimated 75,000 each weekend, hails from San Diego County. (As of this writing, Coachella's producers had not yet released final attendance figures.)

Snoop and Dre displayed an engaging sense of camaraderie during their performance, which sometimes jarringly alternated gangsta rap classics, such as "Nuthin But a 'G' Thang" and "What Up Gangsta" with such recent, pop-friendly, middle-of-the-road songs as Khalifa's "Young, Wild and Free" (which — surprise! — features Snoop). More suitable was 50 Cent's "In The Club," the lyrics of which give shout-outs to Dre and Emniem, the latter of whom was featured Sunday on "I Need a Doctor," "Forgot About Dre" and "'Till I Collapse."

At times, it all seemed like a marketing exercise for the stars' recent and vintage recordings (never mind the fact that Eminem and 50 Cent both rose to fame after being signed to record deals by Dre). But the opportunity to hear these hip-hop legends side by side had considerable appeal, as did the opportunity to contrast Snoop's lazy, hazy delivery with Dre's more sharply articulated flow.

It remains to be seen if Eminem and the other musical guests, living and deceased, are featured when Dre and Snoop headline next Sunday's closing weekend of Coachella. But there was something almost quaint about watching and hearing such a large audience engage in what might be termed gangsta rap nostalgia, given that Dre's landmark album, "The Chronic," was released in 1992. He underscored this point by asking the audience to cheer, depending on how long they had been fans -- in five year increments.

The mass audience sing-alongs during most of their selections inspired smiles, as well as a spirit of bonhomie.. At least they did for anyone who recalled how gangsta-rap was once viewed as an ominous threat to society in general — and impressionable young listeners specifically.

But speculation is building that Dre, Snoop and some of their Coachella guests may re-team this summer for a national tour. Judging by the ecstatic reception they received Sunday, even when executing such questionable moves as sampling Phil Collins' "In The Air Tonight" — could it have been an oblique contact-high reference? — such a concert trek would qualify as anything but a hail mary.